


Evolution

by Noper



Category: Final Fantasy XV
Genre: A/B/O, Alpha/Beta/Omega Dynamics, M/M, Slow build into actual relationships, alpha!Noctis, alpha!Regis, kind of cute, omega!Prompto, pre game
Language: English
Status: In-Progress
Published: 2017-01-11
Updated: 2017-06-15
Packaged: 2018-09-16 22:15:00
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 3,783
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9291773
Author URL: https://archiveofourown.org/users/Noper/pseuds/Noper
Summary: Due to the relaxation of many breeding laws over the centuries the kingdom of Lucis has become a 99% beta population.Niflheim has different ideas and, although omegas are more rare in modern times, the mating laws of old still stand.Prompto's presentation as an omega leads to far too many question about his future but, more worryingly, about his past.





	1. Chapter 1

Prompto had woken up feeling pretty terrible. At first he thought it had been down to staying up into the early hours of the morning playing a game with Noctis. 

He'd only gone to bed when he did because Ignis' voice could be heard through his headset telling Noctis that he needed more than 4 hours of sleep to function at school. 

The blonde hadn't felt tired at all last night but now his alarm was howling at him his head felt like it might explode. 

His parents were already gone, that was typical. Not that Prompto would ever complain about it - he was so grateful for them taking him in and he understood they could only afford to take him because they had good jobs. 

Prompto headed to the kitchen, got himself some coffee and an apple as he leaned against the counter. 

Maybe he should take some painkillers to rid himself of the headache that was pulsing behind his eyes. 

"I'm stronger than that..." He laughed softly to himself and shook his head, managing not to wince even though moving his head wasn't the best idea right now. 

Once his cup was drained he headed out, bag slung across his shoulder as he walked down the street chewing on his apple. 

Prompto found himself singing softly as he practically skipped along - he didn't really understand why the idea of Noctis was making him so excited today. Then again, just the knowledge that Noct was his friend made him happy. 

This was a different type of happy though; it was the kind of happy that made warm blossom out from his chest and spread to the very tips of his fingers and toes. 

He must have been smiling like an idiot when he walked into the classroom and set his eyes on the prince. 

Noctis didn't notice him since he was playing on his phone so Prompto savoured the few moments where he could look at Noctis purely being Noctis - the way his lips quirked up when he beat a part of his game, the way his hand moved through his hair subconsciously whenever he was thinking about his next move...

"Sit. Down!" The teacher called out from the front of the classroom. 

Prompto turned red and scrambled into his seat. 

Unfortunately for the young man he happened to sit behind Noctis, today this meant he couldn't think of anything but the dark haired boy all day. 

He was gnawing on the end of his pen as he watched Noctis' every movement. The prince must be fairly strong thanks to all of his training sessions with Gladio. Prompto wondered if he had a six pack... 

Prompto tensed up when he realised what he was doing - did he like guys? There were plenty of pretty girls he had tried (and failed) to ask out. And, although he always thought of Noct as handsome, he'd never actually wanted to touch him... so why was that changing now? 

He swallowed hard, shifting a little on his seat to try and get comfortable. The headache hadn't gone away and the throbbing had spread through most of his body. Surely that wasn't normal! 

There was an odd little sound in the world and it took Prompto a few seconds to realise the sound had been him. 

"Prom?" 

Prompto blinked as he was brought back to reality - Noctis, and everyone else, had turned to look at him. 

"I..." He swallowed hard, shaking his head to try and clear it but- why was he so damn warm? He felt oddly wet too, between his legs. Sex Ed wasn't the best but he was damn sure guys didn't self lubricate. 

Before the teacher could say anything Prompto picked up his bag and bolted out of the door. 

"Did he wet himself?" One of the boys laughed as the blonde disappeared. 

He didn't think anyone would follow him but he still ran to a bathroom on the opposite side of the school. 

Apparently running didn't help his current pains the way it usually did. Instead the throbbing of his cock and hole just seemed to have doubled. 

The moment he realised he was alone in the room some kind of instincts took over and his hand plunged into his trousers. His whole body shuddered as he pressed a finger against his oddly sensitive, wet hole. This must be a dream. This was impossible. No way could he be an omega. 

"Prom?" Noctis' voice made him jump and he looked up at the other teen, freezing when he realised he was stood in a bathroom... fingering himself in front of his best friend and the crown prince. "What's going on?"


	2. Chapter 2

Noctis had known since he was a little boy that he was an alpha but his father had been quick to assure him that it didn't make him better than betas or omegas or any of their citizens.

His father had explained that by being an alpha they were natural leaders and were more closely connected to nature and the magic that flowed through their veins.

Something he hadn't ever really explained in detail was just how strong his instincts would become if he was ever faced with an omega in heat - Regis hadn't told him about the animalistic, desperate need to shove the omega to the floor and knot them over and over again until their belly was swollen with pups.

But this omega was Prompto, was his best friend... Noctis didn't even think omegas existed in Insomnia anymore. He knew that his mother had been an omega but she wasn't originally from their kingdom.

"Noct... Noctis I need..." Prom swallowed hard.

It was this, the fear and reluctance and shame in his best friend's eyes, that gave Noctis the strength to step out of the bathroom and slam the door shut.

Without Prompto's scent invading his nose directly it was a bit easier to think. Still didn't give him any idea of what actually to do about what was going on with his achingly hard-

He coughed and shook his head desperately, pulling out his phone so that he could call... anyone!

"Hello?" Thankfully his scrambled brain had called Ignis.

"Iggy! Prom smells really good and- fuck- I want to knot him so bad- I can hear him whining... he needs me. He wants it so bad..." Noctis was breathing heavily, unable to help but want to drink in Prompto's scent and sink deep inside his perfect c-

"Noctis." Ignis' voice was stern, full of worry that always gave away how much he cared about the two young men. "You need to stay away from him. I'll come and pick you up. Just wait for ten minutes. Can you do that?" He asked, sounding very much as though he didn't believe Noctis could.

"I... I think so... Gods, Iggy, he smells so fucking good..." Noctis was barely even aware that he was palming his cock through his trousers.

"Wait- He's in... aren't you in rut?"

"No... I don't go into rut. Prom r-ran out and-"

"Noctis..."

The prince could hear Prompto whimpering and could feel the omega trying to open the door. Only Iggy's voice kept him from breeding the sweet creature the way nature intended.

"Shit..." It was so rare for Ignis to swear that Noctis managed to clear his mind enough to keep his weight against the door to ensure it wouldn't open. "Listen to me, Noctis. You need to stay away from Prompto right now. I'll bring to cars. Don't let anyone near Prompto, he'll be in danger or cause panic if this spreads."

Noctis nodded but couldn't muster words since he was working so hard not to drink in Prom's lovely scent.

He hung up the phone and slid to the floor, closing his eyes as he prayed to any Astral that might be listening for no one to come down the corridor because he had a terrible feeling he would attack anyone who tried to come near Prompto.

So long as he convinced himself that he was protecting his om- Prompto from other alphas. Not that there were any other-

He had lost track of time when he heard footsteps coming down the hallway. They were rushed but familiar.

"Iggy..." Noctis moaned softly, blinking up at the man he knew and a stranger.

"He's in a bad way. Long time since I've seen someone this badly messed up by an omega-" The man was somewhat familiar to Noct - one of the Kingsglaive... He smelt like an alpha too but Noctis wasn't sure if that was just his own confusion.

Noctis' lips pulled back in a snarl as his body adjusted so that he was ready to pounce at the man. "Mine..." The word was feral as he lunged at the man.

"Your Highness!" Ignis managed to catch Noctis' arms and pin them behind his back - it was very difficult to hold the young alpha like this but Ignis could manage it a short while.

"Take him home, I'll bring the omega... Um... Prompto. I'll take him to one of the guest rooms." The stranger said softly, clearly trying not to antagonise the prince further.

Noctis snarled and struggled but, soon enough, was in the back of the car with the windows open.

The fresh air cleared his mind surprisingly quickly.

"Prompto! Ignis! Is Prom okay?!" He sat up and looked out of the back window, feeling so bad about what he'd been wanting to do to him.

"Prompto will be fine. Nyx has been given the keys to the guest rooms in the west wing - none of them are in use currently so he won't be disturbed there. Nyx is going to stay Guard while we figure out what to do."

Noctis shifted uncomfortably in his seat as he realised he'd jerked off at least once during his hazy time waiting for Ignis. There were much bigger problems though.

"Iggy.. If Prompto is in heat then that means he's an omega which means... he's not from Insomnia?" The young prince whispered, fear bubbling away in his stomach now his lust had vanished.

"I don't know, Your Highness, I honestly don't know."

**Notes for the Chapter:**

> Anyone want some smut? And, if so, should Ignis 'comfort' Prom or Nyx? Can't be Noctis this early unfortunately :)


	3. Chapter 3

**Notes for the Chapter:**

> Smut after the break (***) Nyx won by a land slide so here you are!  
> Sorry if it's not that good xD

Noctis had lived in his own apartment for a few weeks by now but Ignis had sternly told him that it would be foolish to take Prompto back there - such a small space would make it impossible for Noctis to think clearly.

"How could he be an omega though?!" Noctis asked for what must have been the 7th time.

"I do not know, Noct. We should wait for the heat to be over and then we can ask Prompto about it-"

"But omegas don't exist here anymore! There are a few alphas here and there but no omegas..." He noticed Ignis' gaze shift away uncomfortably. "What?"

"It's not that they don't exist - they are born very rarely but due to the mixing of breeds they don't tend to live that long. I've never known an omega as old as Prompto unless they were from..."

"Unless they were a Nif?!" Noctis was on his feet and striding to the door before he could think twice about it.

They would kill Prom if they believed he was a Nif - they would think he'd been sent here to befriend the prince and gather information. That idea made his skin crawl; Prom would never do anything to hurt Noctis. They were best friends!

"Noctis!" Iggy grabbed his arm to stop him. "If you go anywhere near Prompto it will just make your instincts take over and I have no doubt your father or one of his advisors will discover what is going on!" He pulled the young alpha away from the door.

Noctis blushed when he realised he was whimpering, falling silent as he tried to figure out what to do. "But he's in pain..." The prince whispered.

Ignis nodded slowly as he led Noctis back to the bed and let him sit down. "The man with him, Nyx, has been around omegas in heat before. He offered to help Prompto but said he would wait for your decision."

"W-wait, if he's going to mate him then why can't I-"

"He's not going to bond to him, I doubt he'll even undress." Ignis said quickly, not wanting Noctis to yell or draw any attention. "You've never been around an omega in heat - even if you tried to control yourself you would likely bond to Prompto and then..."

"And then everyone would find out anyway." Noctis let out a growl as he laid back on the bed.

The young alpha was silent for almost a minute as he tried to organise his thoughts. "Tell the man.. Nyx- tell him to make Prom feel better. But that if he bonds him I'll rip his throat out."

  
***

  
Nyx was stood as guard outside the room that held the little blonde omega even though no one came to this corridor - not unless they had a lot of guests. It was a good thing Ignis knew about it.

He found himself gently gnawing on his lip as he thought of the way the om- Prompto pleaded as Nyx scooped him up and loaded him into the back of the car.

The alpha hadn't been around omegas for a while now but he was still more familiar with the tempting, sweet scent that was creeping under the door even now. His training for the Kingsglaive had helped him to grow the control he had over his instincts and he was more than willing to do this for Ignis.

He was so lost in concentration that he jumped when his phone bleeped.

[Text: Ignis] You have Noct's blessing. Be careful.

Nyx's lips quirked up in a little smile when he realised that he could enter the room.

He opened the door, making sure to be slow as he stepped into the room and locked it behind him - he needed to make sure no one came in.

The omega was rather busy on the bed; soft whimpers filled the air as the sweet little thing writhed on the bed, fingers pressed into his slick hole as he tried to achieve release.

Nyx knew the omega wasn't his to claim and he wouldn't try to, he just wanted to stop Prompto's discomfort.

He tugged off his jacket and boots, setting them in front the door before stealing himself to make sure those were the only items of clothing that came off by taking deep breaths of Prompto's scent.

Nyx didn't know the omega so there was no prior connection to his scent, nothing to truly overwhelm the alpha as he stepped over to the bed.

His smile was kind as he settled on the edge of the bed, keeping still as the omega noticed him and breathed in his scent.

"Alpha..."

Nyx was amazed one word could be so full of longing but he kept himself still until Prompto crawled over to him through his own choice.

"Hey..." Nyx greeted, running his fingers soothingly through the young omega's hair. "It's okay, you stay calm and I help the aching stop, deal?"

Prompto whimpered, barely aware of what he was doing as he tried to undo Nyx's trousers.

"No, sorry little one! You'll have to use your imagination." Nyx chuckled softly as he grasped both of Prompto's hands in one of his own and pinned them to the pillows. "Shh... everything is gonna be okay. It's only your first heat, it'll only later a day or two." He promised as his lips brushed over the gland on Prompto's throat that was meant for bonding but Nyx knew just sucking on it would realise 'happy hormones' for the omega.

The alpha couldn't help but be proud as the whimpers turned into soft moans thanks to the licks and gentle sucking of the swollen gland.

When the omega was relaxed enough Nyx's free hand trailed down his body to his virgin hole and pressed two fingers inside him.

Prompto gasped, body jerking a little as Nyx's elegant fingers massaged the sensitive wall of his hole. "More.." He pleaded softly, his want for Noct completely vanishing as his instincts made him crave just any knot.

"I don't think you need any more, bet you're a good little omega who could cum just from this." Nyx said, refusing to give into his own instincts which were screaming at him to take this perfect creature as his own.

He didn't want Prompto's first heat to traumatic. Not only would he feel like shit but he was pretty sure the prince would kill him - he would make Prom feel good and keep him from doing anything he might regret.

"A-ah... Alpha!" Prompto's body trembled as Nyx pushed a third finger into him and continued to gently nip his bonding gland until the omega cried out in pleasure as he orgasmed for the first of many times.

"Good boy, good omega. Keep it up." Nyx purred into his ear, not missing the way his praise made Prompto's eyes light up.

**Notes for the Chapter:**

> I badly want to write more Nyx, he's fun to write even if my smut is meh


	4. Chapter 4

**Notes for the Chapter:**

> I know it's been ages. I'm sorry. Real life has been hectic but now my exams are done and I have all summer! Hopefully will get some more to you soon.

The next 48 hours were a struggle for Nyx, despite his control even he was tested every time the little omega begged for more.

The blonde's eyes were just so sweet, like a puppy who didn't understand that it wasn't time to play for continue to nag for more and more games.

Thankfully he was able to say no, soothing the creature with soft kisses and rougher hands that ran over Prompto's chest to tease his aching chest before always returning to his hole to bring him to the pleasure he knew the omega needed.

Every few hours the alpha would coax him to rest and watch over him. Prompto seemed so small laying in the middle of the bed, the sheets long ago shredded by his teeth and nails in moments of bitter frustration during the few minutes Nyx would leave to get food or water or take care of his own needs.

Nyx had no doubt that if he had remained in the room when the room care of his own erections the omega would have long ago figured out a way to get the knot he had been desiring. The alpha was relieved, and somewhat embarrassed, that it took barely any action on his part to release his pent up want just by thinking of Prompto's scent. At least it meant he kept his breaks brief.

Prompto's scent was fading now, steadily becoming sweet and homely instead of the mind-spinning spice that had filled Nyx's nostrils with each breath over the past two days.

The older male couldn't help the way he savoured the kisses with the omega now, it was nice to have someone so welcoming to his touches when most of the inhabitants of Insomnia would turn their noses up at him even if he was an alpha.

"Hey... shush, it's okay." He soothed as he sat the omega in his lap and made him drink a bottle of water. "You'll be done soon..." Hence why Nyx was trying to keep him in good shape less the king-to-be decided he hadn't taken good enough care of his best friend and became aggressive.

"Who... are you?"

The question took Nyx by surprise as he looked at the sweet man in his arms. He hadn't thought he would come down from the hormones so quickly but maybe he had just misjudged how long the heat would last.

"I'm Nyx. I'm a member of the Glaive. Your friend, Ignis, called me and asked me to help you and your prince out when you started your heat..." The alpha explained slowly and calmly, aware this might also cause an aggressive response if the omega decided he wasn't pleased about being brought to orgasm so, so many times by a random alpha.

His answer, however, was both confusing and endearing as the omega hid his face in Nyx's neck and mumbled something the man only just caught.

"Not my prince."

He smiled and ruffled his hair. "Oh I think that'll be changing pretty soon, I've spoken to him on the phone. He's so protective of you. Now the worst of your heat it over I don't know if he'll calm down or not... but rest assured he is very much yours now." He chuckled and then picked Prompto up as though he weighed no more than a child.

"Where are we going?"

"To get you showered and dressed. Then you can eat while I get your scent off me and we can go find your prince and Ignis and see what to do about all of this..." He tried to keep the worry from his voice but he knew the situation Prompto was in now - as far as he knew no one had told the king about him presenting as an omega but his scent might just give it away now unless the other two had figured out a plan.

***

It had been 48 hours of hell for Prince Noctis.

Ignis had forced him to go into school so that they could pretend everything was normal and the prince could assure his classmates that Prompto was sick.

It was a huge amount of luck that not one of their classmates was anything other than a beta and had never smelt an omega in heat before. Even the teacher accepted the lie with ease, telling Noctis to wish Prompto a speedy recovery.

There were rumours though - a few alphas littered here and there or betas who had alphas who came to pick them up - that there had been an omega in the school. As far as Noctis could figure out no one had linked it to Prompto... yet.

When Noctis wasn't at school he and Ignis found themselves at the public library looking through seemingly ancient books about omegas and how they could be hidden. Whether by design or chance there were very few books relating to this topic so Ignis suggested they looked in the king's private library.

Under the guise of searching for books on rare fish, Regis happily allowed his son and Ignis to explore his extensive collection.

They read late in the night, so late in fact that Noctis' head eventually settled on the table and he drifted into slumber.

Hours of dreaming about the omega passed by before a shout woke him so suddenly he banged his knees on the underside of the table.

"Iggy?"

"This is it! A solution! Come on, we need to go shopping." The older man grabbed his coat and strode of the library, full of purpose and pride at finding a way to protect their friend.


End file.
